Add tmux config

[AlanGreene]

Also investigate:

• [x] session managers:
  • [x] https://github.com/tmuxinator/tmuxinator
  • [x] https://github.com/tmux-python/tmuxp
• [x] save projects / layouts, see session managers above
  • [x] ~/.config/tmuxinator/
• [x] custom style
• [x] key bindings
• [x] https://github.com/AlanGreene/.tmux
• [x] auto start on login to remote (by adding to .bash_profile for example)

  if [ -z "$TMUX" ]; then
  tmux attach -t default || tmux new -s default
  fi